The goal of this program is focused on the training of individuals for careers in toxicological research and service with an emphasis on environmental toxicology. Since this training program was funded in 1979, 48 predoctoral students and 22 postdoctoral fellows have been trained. The program provides training in a multi-disciplinary research environment in association with the development of didactic knowledge through formal instruction in biochemistry, physiology, microbiology, pharmacology, toxicology, immunology, and other health science fields. In the last funding period the training focused on immunotoxicology. The training will retain immunotoxicology as a primary focus and will be widened to also include neurotoxicology and molecular approaches to toxicology. The program has its base in the Pharmacology and Toxicology Department with participants in the Microbiology and Immunology Department. Predoctoral students enter the toxicology training program in their second year and can receive the Ph.D. degree in either department. In addition to fulfilling the requirements of the home department, the students are required to take the basic and advanced courses in toxicology. The students develop communication skills through participation in the student seminar program, journal clubs, and research meetings of the research group with which they are associated. The students perform a research project in an area relevant to toxicology. Areas of research available to the trainees include immunosuppressive and autoimmune-inducing effects of environmentally relevant compounds, carcinogenesis and mutagenesis, intracellular signaling, liver toxicology, and neurobehavioral toxicology of inhaled solvents. The student is guided through the research program by an advisory committee which is responsible for the oral comprehensive examination (second year) and the final defense of thesis (fourth year). Postdoctoral trainees conduct research and participate in the seminar and journal club programs of their home department. In addition, postdoctoral trainees are required to write and submit an application for an individual postdoctoral NRSA fellowship. The training and teaching will be conducted by a community of scientists with a focus on toxicology. The success of the program will be maintained through the addition of new faculty providing new areas of expertise in toxicology.